Rotary valve.



E. R. HOBBS.

ROTARY VALVE.

APPLICATION man 1uNE s. 1916.

Patented Mar. 13, 1917.

N rsmmx Mw @J SN Elbert R. Hobbs.

ELBEBT R. HGBBS, 03F SHL, IDAHO.

recrear vanvn.

Specification of Letters Iatent.

Patented Mar. 13, 1917.

Original application filed December 29, 1915, Serial No. 89,169. Dividedand this application filed June 6,v

To @Z5 whom t may conce/m Be. it known that l, Ennnn'r R. Hoses, acitizen of the United IStates, residing at Buhl, in the county of TwinFalls and State of Idaho, have invented certain new and usefulImprovements in Rotary Valves, of which the following is aspecification, reference being had therein to the accompanying drawing.y

My invention relates to valve systems for fluid engines and moreparticularly to a system of control for rotary valves in reciproeatingengines.

Asn object of my invention is to provide a system of rotary valvecontrol whereby fluid may be let into each side of the engine cylinderat the same rate and in the same quantity.

Further objects of my invention are to provide various novelarrangements and combinations of parts whereby certain new and betterresults may be obtained in the art to which it pertains.

This application is a division of my prior application filed December99, 1915, Serial No. 69,169, for rotary valve gear.

My invention is illustrated in the accompanying drawings in. which-Figure 1 is a plan view, partly in section, o f a fluid engine equippedwith my invention.

Fig. 2 is a plan view of the valve seat.

Fig. 3 is a plan view of the intermediate valve member looking` fromwithin the steam chest.

Fig. e is a plan view, partly in section, of the cap valve member,lookingfrom within the steam chest. y

Referring to the drawings in particular 4 is the enginecylinder,adjoining which is a cylindrical steam chest 5 whose interior isconnected through short steam chiots 6 and 16 leading from opposite endsof the steam chest to the respective opposite ends of the cylinder.` Theducts 6 and 16 terminate in the steam chest in openings 7 and 17 in thevalve seats 1 and 11 respectively. Intermediate valve members 2 and 19engage the valve seats 1 and 11 and are in turn engaged by the capmembers and 13, respectively. The cap members 3 and 13 are connected toeach other by cylindrical telesconing extensions 9 and 19, held in fixedangular relation by means of pins 14 fixed in the extension 9 andengaging longitudi- Serial No. 101,961.

nal slots 15 in the extension 19. rlhese telescoping sections inclose anexhaust space 2() within the steam space 21 and are provided with anannular packing 22 interposed at the sliding joint in order to preventthe leakage of steam between the spaces 20 and 2l. The cap members 3 and13 are rotated by means of the shaft 23 which passes through the member13 and is fixed to the member 3.. This shaft carries a coiledcompression springa 24 adapted to bear against 3 and 13 and hold themagainst the intemediate valve members 2 and 12. The intermediate member12 is rotated by the hollow shaft Q5 to which it is fixed, and carrieswith it the other intermediate member 9 by means of the rigid arms 26fixed to the member 12 and slidably engaging the member rlhis slidableengagement of the pairs of members 2-12 and 3-13 is provided in order topermit the members of each pair to move away from each other to taire upthe wear. 1

The valve members 1-11, 2 12 and 3-13 cooperate in the sam-e manner asthose described in the application previously referred to and differonly in form to adapt them to the arrangement here used. As the members1, Q and 3 are substantially like the members 11, 19 13, respectively, adescription of one set, 1, 2 and 3. will suffice. The engaging orbearing surfaces of the several valve members made conical in shape inorder to keep them in alinement. A single radial opening 7 in the valveseat l connects with the steam duct 6 while a series of arc-shapedopenings 10 near the center of the valve seat lead to an annular exhaustduct 8 connected with the atmosphere or a condenser through a suitablepassage not shown. In the intermediate member 2 is a series o-farc-shaped perforations 36 registering with the openings l0, and onopposite sides of the center are groups of radial perforations 27 and28, an end perforation 29 and 30 in each group communieating with anarc-shaped recess 31 and 3Q, respectively, which recesses open only onthe face engaging the valve seat 1 and are separated from each other atthe ends a distance slightly greater than the width of the opening 7.Sockets 33 are formed in the member 2 near its periphery to engage therigid arms 26, previously referred to, which sockets have their sidewalls parallel to the axial movement between the valve and theV armswhile maintaining a constant angular relation. rIhe cap member 3 isformed with a recess 34 and a perforation 35 each adapted to communicatewith one or more of the perforations in the groups 27 and 28 in theintermediate member, according to therelative angular position of thetwo members, the perforation 35 communicating at all times with theperforation 36. The spaces formed by the perfor-ations and recesses inthe different members 1, 2 and 3 are so arranged and proportioned thatwhen the members are superposed in the relative angular positions shownin Figs. 1, 2 and 3, the recess 34 and perforation 35 will be out ofconnection with the perforations 27 and 28, and the perfor-ations 27 and28 and recesses 31 and 32 out of' connection with the opening 7. rThus,in this position, there is no passage of communication between the valvemembers excepting through the perforations 10, 36 Aand 35 which form theexhaust passage. However, if the cap member 3 is rotated in a clockwisedirection, the recess 34 will be brought into communication with oneor.` several of the kperforations of group 28, according to the amountof rotation, while the perforation 35 will be brought into communicationwith the same num-ber of perforations in the group 27 andv with therecess 31 via the perforation 29. It will be seen that by varying thisadjustment, the amount of steam admitted to the cylinder through theopening 7 at each counterclockwise revolution of the members 2 and 3, asa whole, may be varied.

Relative rotation of the cap and intermediate member is effected bymeans of the concentric shafts 23 and 25 passing through and normallyrotated as a whole with the cylindrical casing 37. The hollow shaft 25is connected in fixed angular relation to the casing through axiallymovable clutch members, one member 38 fixed on the casing and the other39 fixed on the hollow shaft by means of a collar and set screw or othersuitable adjustable connection. The purpose of this clutch connectionbetween the casing and shaft 25 is to allow the valve member .12 to moveaxially to compensate for wear and expansion. The solid shaft 23, whichis lixed atone end to the cap member 3, is journaled at the other end ina journal bracket 40 carried by the casing 37 which journal connectionis such as to allow slight axial movement of the shaft to compensate forwear ofthe cap member 3 and for expansion and contraction of the shaftor other parts. A bevel gear 41 xed to the shaft r23 meshes with a bevelgear 42 journaled in the bracket 43 carried by the easing Formedintegral .with or otherwise fixed to the bevel gear 42 is a pinion 44meshing wth the rack 45 slidably mounted on the casing 37. Thus axialmovement of the rack 45 will be transformed into a relative rotarymovement between the solid shaft 23 and the hollow shaft 25, while whenthe Era-ck is held against axial movement both shafts together with thecasing 37 will remain in fixed relative angular relation.

rlhe casing bears at the end, opposite the steam chest, in a journalsupport 46 mounted in any suitable manner in fixed relation to theengine bed, not shown, and the casing is locked in the journal againstaxial movement by the' annular reduced portion indicated in dotted linesat 47, any expansion or contraction of the casing being compensated forby the clutch members 38, 39.

In order that the rack 45 may be reciprocated while the frame isrotating, it is carried by a rod 48 which connects with a sliding collar49 j ournaled on the outside of the casing and adapted to bereciprocated along the casing by a slip ring 50. in arm 51 controls themovement of the slip ring and collar through a suitable transmissionmechanism comprising the members 52, 53. and 54, the pivot 55 of the armbeing fixed in relation to the engine bed, not shown. A suitable lockingplate 56 is also provided for holding the arm 51 in any adjustment.

The engine shaft 57 is journaled in stationary bearings 58 and 59, andcarries at one end a crank plate 60 connected with the piston 6l by theusual crank pin 62, link 63, wrist pin 64, and piston rod 65.

Motion is transmitted from the engine shaft 57 to the rotatable casing37 through eccentric bevel gears 66 and 67 fixed respectively to theengine shaft and theA casing. rlhese bevel gears are fixed eccentricallyand at an angle with their respective shafts, and in such relation to,veach votherthat they will always be in mesh while their intersectingradii will vary in inverse relation to each other. Thus. the frame 37and with it the valve members 2v and 3 are given a variable speed inrelation to the engine shaft the purpose of which i's to compensate forthe variable speed of the piston and its utility wil-l appear Vfromthe-following, y

vAs the crank pin 62moves from the ex-Y treme right hand position 68,the link 63 connectingthe crank pin with the wrist pin 64, is caused tochange its annular position so that the piston moves a distance equal tothe crank radius plus the difference between the true length of the linkand its'horizontal projection when the pin is in the position 69; and asthe crank pin moves from 69 to 7 O, the piston is moved a distance equalto the crank radius minus the difference between the true length of thelink and the said horizontal projection. 0n the other hand, in the backor return stroke, vthe crank pin moves from 70 to 69 in the firstquarter turn, the piston will move the length of the crank radius minusthe said difference, and then as the crank pin moves from G9 to (3S inthe last back quarter turn the piston will move the length of the crankradius plus the said difference. Thus it will be seen that the pistonmoves faster during the first portion of its forward stroke than duringthe latter portion, while in the back stroke it moy es slower in thefirst portion than in the latter portion.

ln order` to allow the same amount of steam to enter both sides of theengine cylinder and at a rate proportionate to the speed of the piston,the valve must rotate with a greater speed during the latter part of theback stroke and first part of the forward stroke than during the latterpart of the forward stroke and lirst part of the back stroke. Such aresult is accomplished through the relative speed obtained between theengine shaft and the casing 37.

By the use of the novel arrangement of eccentric bevel gears hereinpreviously described, l find that the variable relative motion betweenthe piston and engine shaft can be elfectively compensated for whileusing a symmetrical two-way valve.

The operation of an engine making use of the type of valve shown hereinis set out in detail in the application previously referred to, and itsuffices here to describe a complete cycle of a charge of steam throughone side of the engine cylinder, the cycle of the charge through theother side being identically the same.

Assuming that the intermediate valve member 2 is adjusted so that theinlet recess 34 is in communication with several of the perforations 28,and the exhaust perforation 35 in communication with the recess 3l viathe perforation 29, and also that the space 31 in the steam chest isconnected with a suitable source of steam supply not shown; the steamwill first pass from the space 2l through recess 34, the irst one of theperforations 28, opening 7, steam duct 6, into the cylinder 4: back ofthe piston. As the piston moves forward, the steam continues to enterthe cylinder over the path described through successive perforations 28,the valve starting fast and rotating at a retarding speed during theforward stroke. As the piston nears the end of the forward stroke, theflow of steam is cut off by the movement of the perforations 28 out ofcommunication with the opening 7. At the beginning of the back stroke,the recess 31 is brought into communication with the opening 7 so thatduring the entire back stroke the exhaust steam will pass out toatmosphere or condenser via duct G, opening` 7, recess 31, perforation29, exhaust chamber 20 and perforations 36 and 10. During the backstroke the valve first moves slow and rotates at an accelerated "speedduring the remainder of the stroke, in order to supply steam to theother side of the cylinder at a rate proportionate to the backwardmovement of the piston.

in the driving mechanism of a valve gear it is important that lostmotion be eliminated as nearly as possible, and to this end l havedevised an effective means for taking up the lost motion in the gears,which means l have shown here in the form of a split gear G6. (Seeespecially Figs. l, 5 and lThis consists in splitting or dividing thegear transversely and midway of its thickness and holding the two parts66, 66h, together in such a manner that one may be slightly turned inrelation to`the other and iXed in the adjusted position so as to take upany lost motion due to wear. ItV

will be seen that by such an adjustment the effective width of the teethis increased, the lower portion 661 of the teeth taking the wear whenturning in one direction and the upper portion 66 taking the wear in theopposite direction.

Having thus described my invention what l claim and desire to secure byLetters latent is:

l. In combination, a reciprocating engine having a cylinder andreciprocating piston therefor connected through a pitman and crank to ashaft for rotating the same at a substantially constant rate ofrotation, a rotary valve for controlling the admission of fluid to thecylinder at each side of the piston, and motion translating meansconnected between said valve and said shaft for rotating said valve insubstantially constant relation to the rate of rectilinear movement ofthe piston.

2. In combination, a reciprocating engine, a rotary valve therefor, anda variable motion transmission mechanism between a moving part of theengine and said valve for rotating said valve at a decreasing speedduring the forward stroke of the engine and at an increasing speedduring the back stroke.

3. En combination, a reciprocating engine and shaft therefor rotated ata substantially constant speed, a rotary valve for controlling theadmission of iiuid to the cylinder of the engine, and an operating shafttherefor, and a pair of intermeshing eccentric bevel gears eachconnected to one of said shafts and so proportioned as to cause saidvalve shaft to rotate in substantially constant relation to therectilinear movement of the piston of the engine.

1l. In combination, a reciprocating engine having pitman and crankconnection between the piston and the engine shaft, a

rotary valve for controlling the admission of fluid to the enginecylinder on both sides of the piston with driving means therefor',

and motion transforming means between said v engine shaft and the valvedriving means adapted to compensate for the variable speed ratio betweenthe piston and engine shaft' due to the said pitman connection.

5. 1n a Huid engine, a reciprocating driving part and a rotating drivenpart with a variable speed driving connection between them, a rotaryvalve controlling the supply of fluid to said reciprocating-part, andvariable speed gear connections between said rotating part and saidrotary valve so arranged as to transmit motion from said rotating partto said rotary valve constantly during the operation of thereciprocating part, in a speed ratio inversely proportionai to the speedratio between the reciprocating driving part and the rotating drivenpart of the engine.

In testimony whereof I aiHX my signature.

ELBERT R. HOBBS.

copiesA of this patent may be obtained for ve eentsA each, by addressingthe Commissioner of Patents. Washington, D. C.

